Motor control system for a timer



May 6, 1969 J. A. HIRSCH ET AL MOTOR CONTROL SYSTEM FOR A TIMER Filedsept. 7, 1965 INVENTORS JAMES ARTHUR H/RSCH ROBERT E SHELTON BYERJSENSOR ATTORNEY United States Patent U.S. Cl. 318-102 Claims ABSTRACT OFTHE DISCLOSURE A device for controlling the operation of an applianceincluding means for controlling motor of a timer and a motor of theappliance. The means including sensing means coupled to a power sourceresponsive to a state of the appliance whereby energizing power from thepower source to the motor means of the timer is applied. A switchingmeans operated by the motor means of the timer and coupled to the motormeans of the appliance and to the motor means of the timer forenergizing the motor means of the appliance and for maintaining themotor means of the timer energized during selected time intervals.Another switching means operated by the motor means of the appliance andcoupled to the motor means of the appliance and to the motor means ofthe timer for maintaining the motor means of the timer and the motormeans of the appliance energized.

The present invention relates generally to timers and more particularlyto the means and method for providing a motor control system for atimer. Many appliances are presently being manufactured which requiretimers for establishing automatic operational features. These timersusually comprise a constant speed motor which rotates a plurality ofswitch activating members so as to develop cyclic circuit conditions tocontrol the various component parts of the appliance. For instance, atimer in a washing machine has to provide cyclic circuit conditions toaccommodate the filling of the washer with water, the washing cycle, therinsing cycle, and the spinning cycle.

One of the problems in the past has been to provide a reliable andeconomical means for controlling the motor of a timer so that said motorwill be energized at the proper time and, as a safety factor, so thatsaid motor will continue to be energized during predetermined timeintervals.

Accordingly, the present invention provides a means for meeting theabovementioned requirement. In addition, since most appliances have amotor, the present invention provides a means for controlling said motorof said appliance as well as a means for controlling the motor of thetimer. The invention then is a novel combination which utilizes featuresof a sensor, a solid state control circuit, a cyclic timer, and anappliance motor equippedwith centrifugal switches. It is particularlynovel, in this combination, to use an appliance motor as a means forlatching a particular circuit condition. 1

An attractive feature of the control system of the present invention isthat it is versatile. The sensor which is coupled to the solid statecontrol circuit for the timer motor can take many different forms and,therefore, can be used in many types of applications. The various formswhich the sensor can take will be discussed later in the specification.

It is an object of the present invention, therefore, to provide a meansfor controlling the motor of a timer and for controlling the motor of anappliance which incorporates said timer.

It is another object of the present invention to provide a solid statecircuit which is responsive to a variety of sensors for controlling amotor of a timer.

It is still another object of the present invention to pro vide a meansfor using the motor of an appliance as a latching means for maintainingdesired circuit conditions.

It is a further object of the present invention to provide a means forkeeping a motor of a timer energized when the sensor coupled to themotor control circuit is not in a required state.

The present invention, in another of its aspects, relates to novelfeatures of the instrumentalities described herein for teaching theprincipal object of the invention and to the novel principles employedin the instrumentalities whether or not these features and principlesmay be used in the said object and/or in the said field.

Other objects of the invention and the nature thereof will becomeapparent from the following description considered in conjunction withthe accompanying drawings and wherein like reference numbers describeelements of similar function therein and wherein the scope of theinvention is determined rather from the dependent claims.

For illustrative purposes, the invention will be described inconjunction with the accompanying drawings in which:

FIGURE 1 is a schematic showing how the motor of an appliance is used asa relay.

FIGURE 2 is a schematic showing how the timer motor is energized by asensor and a solid state control circuit.

Generally speaking, the present invention resides in a timer forcontrolling the sequential operation of an appliance and is a means forcontrolling the motor of said timer and the motor of said appliancecomprising, a sensor, a circuit coupled to said sensor and to analternating current power source, said circuit being responsive to apredetermined state of said sensor so as to apply fullwave power fromsaid power source to said motor of said timer, a first cam-switchingmeans coupled to said motor of said timer for energizing said motor ofsaid appliance, a first centrifugal switching means adapted to saidmotor of said appliance so as to keep said motor of said applianceenergized, a second centrifugal switching means adapted to said motor ofsaid appliance so as to keep said motor of said timer energized, asecond cam-switching means coupled to said motor of said timer so as todeenergize said motor of said appliance at predetermined time intervals,and a third cam-switching means coupled to said motor of said timer soas to keep said motor of said timer energized during predetermined timeinterva s.

Referring now to the drawing, and particularly to the schematic ofFIGURE 1, the component parts of the present invention can be visualizedin conjunction with the following description. Timer motor 10, which isa constant speed motor, is adapted so as to provide constant speedrotational motion to cams 11 and 12 which are rotatably mounted oncamshaft 20 of the timer. Cam 11 operates the normally closed contact 13and cam 12 operates the normally open contact 14. A first side of analternating current power source, hereinafter referred to as L1, iscoupled to both contacts 13 and 14 and a second side of said alternatingcurrent power source, hereinafter referred to as L2, is coupled to oneside of the appliance motor, hereinafter referred to as the main motor15. The normally open contact 14 is coupled to the other side of mainmotor 15. Switches 16 and 17 are centrifugal switches actuated by therotation of main motor 15. Linkage 21 coupled switches 16 and 17 to therotor of main motor 15 so as to close said switches when said main motoris energized. Switch 17 coupled terminals 33 and 34 in the timer motor10 control circuit shown in FIGURE 2.

Referring now to FIGURE 2, we see a schematic of the control circuit forthe timer motor 10. Transformer 22 is coupled across an alternatingcurrent power source represented by L3 and L4. A first side of thesecondary coil of transformer 22 is coupled to terminal 19 which iscoupled to a first side of timer motor 10. Terminal 18 couples a secondside of timer motor to ground. A second side of the secondary coil oftransformer 22 is coupled to the anode of diode 25 and the cathode ofdiode 26. The cathode of diode 25 is coupled to the collector oftransistor 27 and the anode of diode 26 is coupled to the emitter oftransistor 27. A resistor 28 is coupled between the collector oftransistor 27 and ground. A resistor 29 is coupled between the emitterand base of transistor 27. A resistor 30 is coupled between the base oftransistor 27 and one side of sensor 31, the other side of said sensorbeing coupled to ground. Normally open switch 17 is adapted so as toshort out diode 25 when closed. One embodiment of the present inventioncould have switch 17 operated by the centrifugal action of main motorshown in FIGURE 1. Normally open contact 23 is adapted so as to shortout diode 25 when closed by the rotation of cam 32.

The sensor 31 is a means for establishing a circuit condition that willdrive transistor 27 into saturation so as to permit full-wave currentflow through the timer motor 10. The only requirement is that sensor 31present a resistance which is less than that resistance which willprevent transistor 27 from being driven into saturation. For example,sensor 31 could be a liquid level sensing means that would present aresistance inversely proportional to the liquid level. As the liquidlevel increases, the resistance of sensor 31 would decrease untiltransistor 27 would be driven into saturation. Likewise, sensor 31 couldbe a temperature sensing resistor with a negative temperaturecoefiicient. As the temperature of a device being controlled wouldincrease, the resistance of the sensor 31 would decrease untiltransistor 27 would be driven into saturation. Specific values ofresistance would be dependent on the specific application of thisinvention and are not necessary to this specification. Because sensor 31can take a variety of forms to accomplish the same purpose, it will bereferred to as a sensor, as a sensing means for providing apredetermined resistance for a predetermined condition of the appliance,as a resistive means for determining a liquid level in said appliance,or as a resistive means for determining a temperature of said appliance.

The cam 11 and contact 13 shown in FIGURE 2, are a cam-switching meansfor open circuiting the appliance motor referred to as a main motor 15.Cam 12 and contact 14 are a cam-switching means for energizing theappliance motor. The cam 32 and contact 23 are a camswitching means forkeeping the motor 10 of the timer energized during predetermined timeintervals. Switch 17, shown in FIGURE 1, is a centrifugal switchingmeans for keeping the motor 10 of the timer energized and switch 16 is acentrifugal switching means for keeping the appliance motor energized.

With the above description of components in mind, and by makingreference to the drawing figures, the following analysis of operationwill serve to convey the functional details of the present invention.Referring again to FIGURE 1, we can see that an alternating currentapplied across L1 and L2 will energize main motor 15 if contact 14 isallowed to close by cam 12. Thus, when timer motor 10 is energized todrive cam 12, contact 14 will close to energize main motor 15. When mainmotor 15 rotates, centrifugal switches 16 and 17, which are normallyopen, are closed by linkage 21. Centrifugal switch 16 keeps currentflowing through the main motor 15 from L1 and L2 and centrifugal switch17 couples terminals 33 and 34 so as to keep timer motor 10 energizedregardless of what happens to sensor 31 shown in FIGURE 2. Once switch16 is closed, the main motor 15 will be energized until normally closedcontacts 13 are opened by cam 11.

Referring now to FIGURE 2, we can discuss the operation of the controlcircuit for the timer motor 10. The alternating current applied acrossL3 and L4 is stepped down by transformer 22 to provide isolation fromline if required, and to develop a voltage necessary for operating timermotor 10 and the control circuit. With the switch 17 and contact 23 inthe position shown, halfwave current flows through the diode 25,resistor 28 and the timer motor 10. The half-wave current is notsufficient to start the timer motor 10. When the resistance of sensor 31is reduced to the point that will permit transistor 27 to be driven tosaturation every other alternation, full-wave current can flow throughtimer motor 10, thereby energizing said timer motor. The full-wavecurrent will continue to flow through timer motor 10 as long as sensor31 presents the correct resistance or when switch 17 is closed or whencontact 23 is closed by cam 32. Switch 17 is closed by the rotation ofthe main motor 15, shown in FIGURE 1, so as to prevent stoppage of timermotor 10 regardless of what happens to sensor 31.

Now if we assume that the present invention has been applied to awashing machine which is controlled by a timer, the following analysiswill serve to describe a practical application. Sensor 31 could beadapted to determine the level of water in the washing machine and topresent the correct resistance when the water is at a desired level.When the correct resistance is presented by sensor 31 the timer motor 10would be energized and would rotate cam 12, shown in FIGURE 1, to closecontact 1 4 to energize the main motor 15 of the Washing machine. Anextra centrifugal switch could be operated by main motor 15 to close asolenoid-operated valve, thereby preventing flow of water into thewashing machine. The main motor will continue to run until normallyclosed contact 13 is opened by cam 11 which is rotated by timer motor10. In this manner the timer would control the operation of the washingmachine. Other applications of the present invention may be derivedmerely by changing the sensor 31 and providing different cam-switchingfunctions for the timer.

The control circuitry of the present invention, as herein-beforedescribed in one of its embodiments, is merely illustrative and notexhaustive in scope. Since many widely different embodiments of theinvention may be made without departing from the scope thereof, it isintended that all matter contained in the above description and shown inthe accompanying drawing shall be interposed as illustrative and not ina limiting sense.

What is claimed is:

1. In a device for controlling the operation of an appliance, means forcontrolling motor means of a timer means and motor means of saidappliance comprising, a sensor, a circuit coupled to said sensor and toan alternating current power source, said circuit being responsive to apredetermined state of said sensor so as to apply fullwave power fromsaid power source to motor means of a timer through said circuit, firstcam operated switching means operated by said motor means of said timerand coupled between said power source and motor means of an appliancefor energizing said motor means of said appliance, first centrifugalswitching means operated by said motor means of said appliance andcoupled between said power source and said motor means of said applianceso as to keep said motor means of said appliance energized, secondcentrifugal switching means operated by said motor means of saidappliance and coupled between said power source and said motor means ofsaid timer so as to keep said motor means of said timer energized,second cam operated switching means operated by said motor means of saidtimer and coupled between said power source and said motor of saidappliance so as to de-energize said motor of said appliance duringpredetermined time intervals, and third cam operated switching meansoperated by said motor of said timer and coupled between said powersource and said motor of said timer so as to keep said motor means ofsaid timer energized during predetermined time intervals.

2. In a device for controlling the operation of an appliance, means forcontrolling motor means of a timer meansand motor means of saidappliance comprising, sensing means for providing a predeterminedresistance inresponse to a predetermined condition of said appliance, asolid state circuit coupled to said sensing means and to an alternatingcurrent power source, said circuit being responsive to saidpredetermined'resistance of said sensing means so as to apply full-wavepower from said power source to motor means of a timer through saidcircuit, first cam operated switching means operated by said motor meansof said timer and coupled between said power source and motor means ofan appliance for energizing said motor means of said appliance, firstcentrifugal switching means operated by said motor means of saidappliance and coupled between said power source and said motor means ofsaid appliance so as to keep said motor means of said applianceenergized, second centrifugal switching means operated by saidmotormeans of said appliance and coupled between said power source and saidmotor means of said timer so as to keep said motor means of said timerenergized, second cam operated switching means operated by saidmotormeans of said timer and coupled between said power source and said motorof said appliance so as to de-energize said motor means of saidappliance during predetermined time intervals, and third cam operatedswitching means operated by said motor means of said timer and coupledbetween said power source and said motor means of said timer so as tokeep said motor means of said timer energized during predetermined timeintervals.

3. In a device for controlling the operation of an appliance as claimedin claim 2, wherein said means for controlling said motor means of saidtimer comprises first and second diodes, a first side of said powersource coupled to an anode of said first diode and a cathode of saidsecond diode, a second side of said power source coupled to a first sideof said motor means, first resistor means coupled between the cathode ofsaid first diode and a second side of said motor means permittingcurrent fiow from said power source in a first direction through saidmotor means, the anode of said second diode coupled to an emitter oftransistor means, second resistor means coupled between said emitter anda base of said transistor means, third resistor means coupled betweensaid base of said transistor means and a first side of said sensingmeans, said first resistor means coupled between a collector of saidtransistor means and a second side of said cam operated switching meansoperated by said motor means of said timer and coupled between saidpower source and said motor of said appliance so as to de-energize saidmotor means of said appliance during predetermined time intervals, andthird cam operated switching means operated by said motor means of saidtimer and coupled between said power source and said motor means of saidtimer so as to keep said motor means of said timer energized duringpredetermined time intervals.

4. In a device for controlling the operation of an appliance, means forcontrolling motor means of timer means and motor means of said appliancecomprising, a sensor, a circuit coupled to said sensor and to analternating current power source, said circuit being responsive to apredetermined state of said sensor so as to apply full wave power fromsaid power source to motor means of a timer through said circuit, aplurality of cam operated switching means actuated by said motor meansof said timer and coupled to motor means of an appliance and to saidmotor means of said timer for energizing said motor means of saidappliance and for keeping said motor means of said timer energizedduring predetermined time intervals, and a plurality of centrifugalswitching means operated by said motor means of said appliance andcoupled to said motor means of said appliance and to said motor means ofsaid timer for keeping said motor means of said timer and said motormeans of said appliance energized.

5. In a device for controlling the operation of an appliance as claimedin claim 4, wherein said sensor includes means activated by adeterminable liquid level in said appliance, said circuit responsive tosaid activated means of said sensor so as to apply full wave power fromsaid power source to said motor means of said timer.

6. In a device for controlling the operation of an ap pliance as claimedin claim 4, wherein said sensor in cludes means activated by adeterminable temperature in said appliance, said circuit responsive tosaid activated means of said sensor so as to apply full wave power fromsaid power source to said motor of said timer.

7. In a device for controlling the operation of an appliance, means forcontrolling the motor means of a timer means and motor means of saidappliance comprising, an alternating current power source, a diodecoupled in series with motor means of a timer, said diode being coupledto said alternating current power source so as to permit current flow ina first direction through said motor means of said timer, a solid statecircuit coupled to said motor means of said timer and to saidalternating current power source, sensing means for providing apredetermined resistance in response to a predetermined condition of anappliance, said sensing means coupled to said solid state circuit, saidsolid state circuit responsive to said predetermined resistance of saidsensing means so as to permit current flow from said alternating currentpower source in a second direction through said motor means of saidtimer thereby energizing said motor means of said timer, a plurality ofcam operated switching means actuated by said motor means of said timerand coupled to motor means of said appliance and to said motor means ofsaid timer for energizing said motor means of said appliance and forkeeping said motor means of said timer energized during predeterminedtime intervals, and centrifugal switching means operated by said motormeans of said appliance and coupled to said motor means of saidappliance and to said motor means of said timer for keeping said motormeans of said timer and said motor means of said appliance energized.

8. In a device for controlling the sequential operation of an appliance,means for controlling the motor means of a timer means and motor meansof said appliance comprising, an alternating current power source, adiode coupled in series with said motor means of said timer, said diodebeing coupled to said alternating current power source so as to permitcurrent flow in a first direction through motor means of a timer, asolid state circuit coupled to said motor means of said timer and tosaid alternating current power source, resistive means for determining aliquid level in said appliance, said resistive means being coupled tosaid solid state circuit, said solid state circuit responsive to apredetermined resistance of said resistive means so as to permit currentflow from said alternating current power source in a second directionthrough said motor means of said timer, thereby energizing said motor ofsaid timer, a plurality of cam operated switching means actuated by saidmotor means of said timer and coupled to motor means of an appliance andto said motor means of said timer for energizing said motor means ofsaid appliance and for keeping said motor of said timer energized duringpredetermined time intervals, and centrifugal switching means operatedby said motor means of said appliance and coupled to said motor means ofsaid appliance and to said motor means of said timer for keeping saidmotor means of said timer and said motor means of said applianceenergized.

9. In a device for controlling the operation of an appliance, means forcontrolling motor means of a timer means and motor means of saidappliance comprising,

sensing means coupled to a power source, said sensing means responsiveto a predetermined state of said appliance so as to apply energizingpower from said power source to motor means of a timer, a plurality ofswitching means operated by said motor means of said timer and coupledto motor means of an appliance and to said motor means of said timer forenergizing said motor means of said appliance and for keeping said motormeans of said timer energized during predetermined time intervals, andanother switching means operated by said motor means of said applianceand coupled to said motor means of said appliance and to said motormeans of said timer for keeping said motor means of said timer and saidmotor means of said appliance energized independent of said sensingmeans.

10. In a device for controlling the operation of an appliance, means forcontrolling operating means of a timer means and operating means of saidappliance comprising, sensing means coupled to a power source, saidsensing means responsive to a predetermined state of said appliance soas to apply energizing power from said power source to operating meansof a timer, a plurality of switching means operated by said operatingmeans of said timer and coupled to operating means of an appliance andto said means of said timer for energizing said operating means of saidappliance and for keeping said operating means of said timer energizedduring predetermined time intervals, and another switching meansoperated by said operating means of said appliance and coupled to saidoperating means of said appliance and to said means of said timer forkeeping said operating means of said timer and said operating means ofsaid appliance energized independent of said sensing means.

References Cited UNITED STATES PATENTS 7/1962 Bahra 318-486 X 4/1966Bowman 318486 X U.S. C1. X.R.

